In the prior art, various types of gripping devices are known which are used in combination with a robot arm for picking up and displacing objects.
In order to automate the processing of workpieces in the case of medium/large series, specially adapted attachments for robot arms are known, by means of which relatively heavy products, such as workpieces which may possibly, together with the clamping devices and the like, weigh tens to hundreds of kilos can be displaced. Such gripping devices are specifically designed for the object to be displaced. This is particularly true of the shape of the gripping fingers. As a result thereof, such gripping devices can only be used for producing medium/large series.
Until now, small series, that is to say of for example 5-100 pieces, have been positioned in processing stations partly by hand. In this case, it has become customary to feed the various products automatically to the various processing machines, but changeovers still require human intervention. Another example of a complicated operation is the re-setting of objects for which PCT application PCT/NL2009/050587 offers a solution. Another complicated step is the changeover from one product to another product. In practice, it appears that the product changeover often has to be carried out manually. Another problem occurs in the case of castings and/or freely formed parts. For this purpose, expensive automatic clamping devices for automatic loading have been developed and for this reason, clamping is carried out manually in the case of small series.
U.S. Pat. No. 5,184,861 discloses a gripping device, wherein the gripping fingers are rigidly connected with a slide and can be moved to each other, from each other respectively.
The extremities of the gripping fingers are provided with rollers, wherein between an auxiliary part with a defined shape can be received, wherein a further object can be arranged on the auxiliary part which can be manipulated with a tool being between the gripping fingers.
DE 10 2005 058312 discloses part of a robot arm which can be drifted over a limited angle.